139021793 has 2 divisors, whose sum is σ = 139021794. Its totient is φ = 139021792.

The previous prime is 139021789. The next prime is 139021807. The reversal of 139021793 is 397120931.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 138462289 + 559504 = 11767^2 + 748^2 .

It is an emirp because it is prime and its reverse (397120931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 139021793 - 2² = 139021789 is a prime.

It is not a weakly prime, because it can be changed into another prime (139023793) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69510896 + 69510897.

It is an arithmetic number, because the mean of its divisors is an integer number (69510897).

Almost surely, 2^139021793 is an apocalyptic number.

It is an amenable number.

139021793 is a deficient number, since it is larger than the sum of its proper divisors (1).

139021793 is an equidigital number, since it uses as much as digits as its factorization.

139021793 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10206, while the sum is 35.

The square root of 139021793 is about 11790.7503153955. The cubic root of 139021793 is about 518.0372172541.

The spelling of 139021793 in words is "one hundred thirty-nine million, twenty-one thousand, seven hundred ninety-three".